The present invention relates generally to a vehicle ramp system for elevating all four wheels of a vehicle off of the ground to create clearance under the vehicle for a person to easily work therebeneath. More specifically, the present invention relates to a modular vehicle ramp system for elevating all four wheels of a vehicle off of the ground to create clearance under the vehicle wherein the ramp is reconfigurable with a vehicle positioned thereon to allow a user easy access beneath the elevated vehicle.
Typically in the art, portable car ramps are used for increasing vertical clearance beneath a vehicle. In this manner, the ramps are positioned on a flat horizontal garage floor, driveway, yard or like support medium, with the wheels of the vehicle elevated thereon so that a worker can repair or service the vehicle from the underside thereof. A typical portable car ramp includes a bottom structure that engages with a support surface in a stable manner, a generally level wheel support substantially parallel to but elevated above the support surface and an inclined surface that extends from the support surface upwardly to the wheel support. The vehicle wheel is then rolled up the inclined surface to the elevated wheel wherein the wheel of the vehicle is maintained in an elevated position thereby increasing the clearance beneath the vehicle providing access thereto. Should the user desire both that sides of the vehicle frame be elevated, two matching ramps are used, where either both front wheels or both rear wheels are simultaneously rolled up the respective ramps and onto the respective wheel supports.
Such ramps are typically constructed of formed steel, which is painted. This produces a strong, economical ramp but the ramps are relatively heavy. Another approach is to mold the ramps from plastic with internal webs extending between external walls of relatively thin width to achieve adequate strength. While lighter than steel, the plastic ramps are still heavy enough to not be easily handled. Further, these systems are typically not modular in construction and therefore do not provide flexibility in arrangement and use of the ramps.
In the prior art there are several modular wheel ramp assemblies disclosed such as in U.S. Pat. No. 4,920,596, which includes a two level ramp device composed of a first ramp segment attachable at a rear portion to a second ramp segment that itself includes a first support level, which is in turn attachable at a rear portion to a third ramp having a second support level for positioning a car wheel thereon. The design of the first and second ramps requires alignment end-to-end and assembly of the units by positioning each axially before connection to the respective pairs of end brackets. If a car wheel is driven onto the first ramp without the second and third ramps portion attached, the first ramp can “kick-out” or slide away from the wheel due to the limited bottom surface area contacting against the ground surface. Use of this type of ramp device requires assembly before a car wheel progresses to an elevated height to allow aligning of each rear portion of second and third ramps when unweighted to protect the user from “kick-out” by the ramp device. Further, this type of ramp device requires end-to-end alignment for proper cradling by the end brackets extended from each rear portion of each ramp segment, thereby posing an unsafe situation if the operator attempted to assemble or reconfigure the aligned ramp segments while a front or rear wheel is on a first ramp segment and is partially elevated above a ground surface.
A leveling ramp device for a vehicle tire is disclosed in U.S. Pat. No. 4,427,179, that includes a plurality of planar planks that are stacked with their front ends forming a stairway for a wheel to climb, and having rear ends enclosed by a back frame having side members enclosing side wall portions of each stacked plank. Each ramp plank is further held in place by a downwardly projecting dowel that is inserted in the top surface of the next lower ramp plank to maintain alignment of the front portions of the stacked ramp planks. The plurality of ramp planks must be aligned, stacked and enclosed by the back frame before a vehicle tire is moved up the front end surfaces, otherwise the planks will be pushed sideways or backwards without the back frame and interlocking dowels in place. A vehicle tire cannot be positioned in a partially elevated horizontal position other than on an uppermost surface and additional ramp planks must be added before the tire is initially positioned at the uppermost height.
Additionally, an elevating and leveling ramp device for a vehicle wheel is disclosed in U.S. Pat. No. 3,752,441, that is formed using a plurality of hollow blocks having step-like sections that are nestable within the next larger hollow block. The elevating and leveling ramp device allows for extension of each hollow block from the next larger block to form a series of steps on which a vehicle wheel is moved. During extension of respective hollow blocks from the next larger hollow block, the respective blocks are aligned and connected end-to-end, but are not laterally movable for disassembly while the vehicle wheel is positioned on any of the blocks. Therefore, any larger hollow blocks must be added to the ramp device before a vehicle wheel is moved on a low height block or on a middle height block.
In addition to the various problems identified above, another problem encountered in the prior art is the tendency for the bottom edges of the sidewalls of both the steel and molded plastic ramps to sink into gravel or earth surfaces or to be easily tipped when in use. Further, the edges of side walls of formed steel ramps can damage asphalt paving and the side walls of plastic ramps can be easily collapsed if the ramp is misaligned with the vehicle wheels to a degree that the tires push the ramp sideways, bending the same such that the walls collapse under the weight of the vehicle.
There is therefore a need for a modular ramp construction that can be reconfigured with the vehicle in place thereon to allow easier access to the underside of the vehicle. There is a further need for a lightweight but durable and stable modular ramp that is useable on softer surfaces and which can easily be rearranged into many different configurations. There is still a need for a modular ramp system that can easily be rearranged into many different configurations and is constructed using lightweight monolithic materials that are highly durable while also increasing the overall stability of the ramp system.